Proposal Request Synopsis
The Ocean Foundation is seeking an institution (or partnership of institutions) in the Pacific Islands to serve as a regional training hub for ocean acidification for the broader Pacific Islands community. This request for proposals to host the hub is part of a larger project that seeks to build capacity in the Pacific Islands to monitor and respond to ocean acidification through the distribution of equipment, training, and ongoing mentorship. The Ocean Foundation hopes to work with the selected regional training hub to identify additional sources of funding and resources to support the hub in perpetuity, but is unable to guarantee more than the funding laid out below. The regional training hub will be a critical partner in this project and will play a role in sustaining ocean acidification monitoring and research in the region beyond the three-year
time frame of this project. Eligibility and instructions to apply are included in this request for proposals. Proposals are due no later than April 1st, 2021 and should be sent to ioai@oceanfdn.org .
Archive for February, 2021
Request for proposals for a regional training hub for ocean acidification in the Pacific Islands
Published 12 February 2021 Program , Projects ClosedBottom trawling threatens future climate refugia of Rhodoliths globally
Published 12 February 2021 Science ClosedTags: adaptation, biological response, fisheries, globalmodeling, modeling, protists
Climate driven range shifts are driving the redistribution of marine species and threatening the functioning and stability of marine ecosystems. For species that are the structural basis of marine ecosystems, such effects can be magnified into drastic loss of ecosystem functioning and resilience. Rhodoliths are unattached calcareous red algae that provide key complex three-dimensional habitats for highly diverse biological communities. These globally distributed biodiversity hotspots are increasingly threatened by ongoing environmental changes, mainly ocean acidification and warming, with wide negative impacts anticipated in the years to come. These are superimposed upon major local stressors caused by direct destructive impacts, such as bottom trawling, which act synergistically in the deterioration of the rhodolith ecosystem health and function. Anticipating the potential impacts of future environmental changes on the rhodolith biome may inform timely mitigation strategies integrating local effects of bottom trawling over vulnerable areas at global scales. This study aimed to identify future climate refugia, as regions where persistence is predicted under contrasting climate scenarios, and to analyze their trawling threat levels. This was approached by developing species distribution models with ecologically relevant environmental predictors, combined with the development of a global bottom trawling intensity index to identify heavily fished regions overlaying rhodoliths. Our results revealed the importance of light, thermal stress and pH driving the global distribution of rhodoliths. Future projections showed poleward expansions and contractions of suitable habitats at lower latitudes, structuring cryptic depth refugia, particularly evident under the more severe warming scenario RCP 8.5. Our results suggest that if management and conservation measures are not taken, bottom trawling may directly threaten the persistence of key rhodolith refugia. Since rhodoliths have slow growth rates, high sensitivity and ecological importance, understanding how their current and future distribution might be susceptible to bottom trawling pressure, may contribute to determine the fate of both the species and their associated communities.
Continue reading ‘Bottom trawling threatens future climate refugia of Rhodoliths globally’Surface CO2 system dynamics in the Gulf of Anadyr during the open water season
Published 12 February 2021 Science ClosedTags: chemistry, North Pacific
Highlights
- Drivers and mechanisms responsible for the spatial variations in surface seawater CO2 system and associated air–sea CO2 fluxes for the Gulf of Anadyr are identified.
- The decisive impact of the biological factor on the spatial variability of pCO2 in the surface waters during open water season is shown.
- Calculated CO2 fluxes indicate the region is a large sink for atmospheric CO2 during open water season.
Abstract
The Gulf of Anadyr (GA), one of the largest and most poorly investigated gulfs of the Bering Sea, is an important part of the Pacific Arctic. Drivers and mechanisms responsible for the spatial variations in surface seawater CO2 system parameters and associated air–sea CO2 fluxes were investigated during three oceanographic cruises conducted in the GA during the open water season of 1992, 2002, and 2011. It was shown that the surface waters of the GA were moderate to strong sinks for atmospheric CO2 during this season: mean air-sea CO2 fluxes for the investigated areas of the GA, for the three cruises, were -31, -15, and -30 mmol CO2 m−2 d−1, respectively. The summer air-sea CO2 flux was attributed to intensive phytoplankton bloom, and fall CO2 uptake coincided with a period of strong winds and seasonal enhanced primary production. The surface waters of the GA were supersaturated with respect to aragonite during the investigated period. Anadyr Strait, a region of high hydrodynamic activity, was the only area where CO2 efflux was observed. Surface waters of the strait were supersaturated with respect to CO2 and in quasi-equilibrium with respect to aragonite. We found that during the late summer/fall season, the Anadyr Current exported a well-mixed, relatively cold, salty, nutrient- and CO2-rich water through the western Anadyr Strait into the Chirikov Basin. Our research highlights the need for mesoscale studies of the western Bering Sea to produce the most accurate assessment of the regional CO2 budget.
Continue reading ‘Surface CO2 system dynamics in the Gulf of Anadyr during the open water season’Adaptive responses of free‐living and symbiotic microalgae to simulated future ocean conditions
Published 12 February 2021 Science ClosedTags: adaptation, biological response, laboratory, multiple factors, phytoplankton, prokaryotes, review, temperature
Marine microalgae are a diverse group of microscopic eukaryotic and prokaryotic organisms capable of photosynthesis. They are important primary producers and carbon sinks but their physiology and persistence are severely affected by global climate change. Powerful experimental evolution technologies are being used to examine the potential of microalgae to respond adaptively to current and predicted future conditions, as well as to develop resources to facilitate species conservation and restoration of ecosystem functions. This review synthesizes findings and insights from experimental evolution studies of marine microalgae in response to elevated temperature and/or pCO2. Adaptation to these environmental conditions has been observed in many studies of marine dinoflagellates, diatoms and coccolithophores. An enhancement in traits such as growth and photo‐physiological performance and an increase in upper thermal limit have been shown to be possible, although the extent and rate of change differ between microalgal taxa. Studies employing multiple monoclonal replicates showed variation in responses among replicates and revealed the stochasticity of mutations. The work to date is already providing valuable information on species’ climate sensitivity or resilience to managers and policy‐makers but extrapolating these insights to ecosystem and community level impacts continues to be a challenge. We recommend future work should include in situ experiments, diurnal and seasonal fluctuations, multiple drivers and multiple starting genotypes. Fitness trade‐offs, stable versus plastic responses and the genetic bases of the changes also need investigating, and the incorporation of genome resequencing into experimental designs will be invaluable.
Continue reading ‘Adaptive responses of free‐living and symbiotic microalgae to simulated future ocean conditions’Ocean circulation drives the variability of the carbon system in the Eastern Tropical Atlantic
Published 12 February 2021 Science ClosedTags: chemistry, North Atlantic, South Atlantic
The carbon system in the eastern tropical Atlantic remains poorly known. The variability and drivers of the carbon system are assessed using surface dissolved inorganic carbon (DIC), alkalinity (TA) and fugacity of CO2 (fCO2) measured in the 12° N–12° S, 12° W–12° E region from 2005 to 2019. A relationship linking DIC to temperature, salinity and year has been determined, with salinity being the strongest predictor. The seasonal variations of DIC, ranging from 80 to 120 mol kg−1, are more important than the year-to-year variability that is less than 50 mol kg−1 over the 2010–2019 period. DIC and TA concentrations are lower in the northern part of the basin where surface waters are fresher and warmer. Carbon supply dominates over biological carbon uptake during the productive upwelling period from July to September. The lowest DIC and TA are located in the Congo plume. The influence of the Congo is still observed at the mooring at 6° S, 8° E as shown by large salinity and chlorophyll variations. Nevertheless, this site is a source of CO2 emissions into the atmosphere.
Continue reading ‘Ocean circulation drives the variability of the carbon system in the Eastern Tropical Atlantic’Welfare of scaleless fish, Sagor catfish (Hexanematichthyssagor) juveniles under different carbon dioxide concentrations
Published 12 February 2021 Science ClosedTags: biological response, fish, laboratory, morphology, physiology
Increased acidification has shown to bring negative impacts on marine fish. Currently, fish with scales have been extensively investigated, whereas a few systematic studies have been carried out for investigating impacts of acidified environment towards the growth of scaleless fish. Thus, this research aimed to evaluate carbon dioxide, CO2‐induced acidification impacts towards the welfare (growth with health) of the commercially aquaculture scaleless fish, Sagor catfish (Hexanematichthys sagor) for 20 weeks. Fish specimens were exposed to control pCO2 (400 µatm), mild pCO2 (550 µatm) and high pCO2 (900 µatm). Growth were measured by feed conversion ratio (FCR) plus specific growth rate (SGR). The outcomes indicated that the significantly lowest SGR was flaunted in high pCO2 group supported with the significantly highest FCR indicating poor growth. Health parameters significantly showed the highest value of red blood cell, haematocrit, haemoglobin, white blood cell, thrombocyte, mean corpuscular volume and haemoglobin in control group while urea, cholesterol, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, serum cortisol plus glucose were significantly the lowest in control pCO2 with regard to mild and high pCO2 group. These findings can serve as important baseline data in formulating managements regarding the specific effects of acidification on scaleless fish.
Continue reading ‘Welfare of scaleless fish, Sagor catfish (Hexanematichthyssagor) juveniles under different carbon dioxide concentrations’The dual benefit of ocean acidification for the laminarialean kelp, Saccharina latissima: enhanced growth and reduced herbivory
Published 11 February 2021 Science ClosedTags: algae, biological response, laboratory, mollusks, morphology, multiple factors, nutrients, performance
The laminarialean kelp, Saccharina latissima, is a common macroalgae along rocky shorelines that is also frequently used in aquaculture. This study examined how ocean acidification may alter the growth of S. latissima as well as grazing on S. latissima by the gastropod, Lacuna vincta. Under elevated nutrients, S. latissima experienced significantly enhanced growth at pCO2 levels >1,200 µatm compared to ambient pCO2 (~400 µatm). Elevated pCO2 (>830 µatm) also significantly reduced herbivory of L. vincta grazing on S. latissima relative to ambient pCO2. There was no difference in grazing of S. latissima previously grown under elevated or ambient pCO2, suggesting lowered herbivory was due to harm to the gastropods rather than alteration of the biochemical composition of the kelp. Decreased herbivory was specifically elicited when L. vincta were exposed to elevated pCO2 in the absence of food for >18 h prior to grazing, with reduced grazing persisting 72 h. Elevated growth of S. latissima and reduced grazing by L. vincta at 1,200 µatm pCO2 combined to increase net growth rates of S. latissima by more than four-fold relative to ambient pCO2. L. vincta consumed 70% of daily production by S. latissima under ambient pCO2 but only 38% and 9% at 800 µatm and 1,200 µatm, respectively. Collectively, decreased grazing by L. vincta coupled with enhanced growth of S. latissima under elevated pCO2 demonstrates that increased CO2 associated with climate change and/or coastal processes will dually benefit commercially and ecologically important kelps by both promoting growth and reducing grazing pressure.
Continue reading ‘The dual benefit of ocean acidification for the laminarialean kelp, Saccharina latissima: enhanced growth and reduced herbivory’A review of the potential effects of climate change on disseminated neoplasia with an emphasis on efficient detection in marine bivalve populations
Published 11 February 2021 Science ClosedTags: biological response, mollusks, review, virus
Highlights
- Ocean warming is likely to favour disseminated neoplasia outbreaks.
- The effect of seasonality on disseminated neoplasia seems species specific.
- Detailed prevalence and environmental data are required to understand outbreak dynamics.
- State of the art detection methods will be of key importance to obtain insights.
Abstract
Climate change not only directly impacts marine environments by shifting water temperatures, salinity, pH and dissolved oxygen concentrations, but may also indirectly contribute to the emergence of additional ecosystem stressors, such as infectious diseases, including bivalve disseminated neoplasia. Disseminated neoplasia, a form of cancer found in some bivalves – recently discovered to be transmissible in at least six species – has been shown to impair bivalve health and fitness, with occasional mass outbreaks causing high levels of mortality. As the ability of the host bivalve to respond to disseminated neoplasia, and the survival and transmissibility of disseminated neoplasia both depend on environmental factors, it is crucial to understand the interaction between climate change and disseminated neoplasia epidemiology. Furthermore, with bivalves being species of high ecological and economic importance, there is a rising need for the development of efficient disseminated neoplasia detection tools in order to explore potential effects, mitigate and potentially prevent deleterious disseminated neoplasia outbreaks. Therefore, in this study, we reviewed the current knowledge of climate impacted environmental parameters on disseminated neoplasia and identified good practices and methodology for the detection of transmissible disseminated neoplasia in the wild. By exploring the potential effects changing climate has on disseminated neoplasia dynamics, we identified future research directions in order to advance the field. This included using state of the art disease detection methods and taking in account species’ ecological niches to understand the dynamic of disseminated neoplasia outbreaks in the wild and to investigate whether disseminated neoplasia is present in freshwater ecosystems. Finally, we provided a comprehensive step-by-step guideline for an evidence-based detection of this disease in marine ecosystems.
Continue reading ‘A review of the potential effects of climate change on disseminated neoplasia with an emphasis on efficient detection in marine bivalve populations’WHOI working to address increasing ocean acidification; protect region’s vital shellfish industry
Published 10 February 2021 Press releases Closed
Addressing the growing problem of ocean acidification in New England waters before it severely damages the region’s crucial shellfish industry is the focus of an important report by a commission of Massachusetts legislators, state environmental agencies, marine research and conservation organizations, and shellfish industry leaders. Woods Hole Oceanographic Institution (WHOI) is a part of the 18-member Massachusetts Special Legislative Commission on Ocean Acidification and helped co-author the 84-page report released today.
Continue reading ‘WHOI working to address increasing ocean acidification; protect region’s vital shellfish industry’Report on the ocean acidification crisis in Massachusetts
Published 10 February 2021 Newsletters and reports ClosedTags: policy
Since the industrial revolution, the world’s oceans have become increasingly acidic. The main drivers of ocean acidification in Massachusetts are (1) global increases in atmospheric carbon dioxide resulting from anthropogenic emissions, and (2) local nutrient pollution leading to the eutrophication of coastal waters.
Many marine species that evolved under less acidic conditions are threatened by ocean acidification, including some that are critical to the Massachusetts economy. Species that are both economically important and vulnerable to acidification include mollusks such as the sea scallop and eastern oyster.
Massachusetts will be disproportionately affected by ocean acidification due to the relative importance of its coastal economies and environments.
Continue reading ‘Report on the ocean acidification crisis in Massachusetts’Synoptic assessment of coastal total alkalinity through community science
Published 10 February 2021 Science ClosedTags: chemistry, field, methods, North Atlantic
Comprehensive sampling of the carbonate system in estuaries and coastal waters can be difficult and expensive because of the complex and heterogeneous nature of near-shore environments. We show that sample collection by community science programs is a viable strategy for expanding estuarine carbonate system monitoring and prioritizing regions for more targeted assessment. ‘Shell Day’ was a single-day regional water monitoring event coordinating coastal carbonate chemistry observations by 59 community science programs and seven research institutions in the northeastern United States, in which 410 total alkalinity (TA) samples from 86 stations were collected. Field replicates collected at both low and high tides had a mean standard deviation between replicates of 3.6 ± 0.3 µmol kg−1 (σmean ± SE, n = 145) or 0.20 ± 0.02%. This level of precision demonstrates that with adequate protocols for sample collection, handling, storage, and analysis, community science programs are able to collect TA samples leading to high-quality analyses and data. Despite correlations between salinity, temperature, and TA observed at multiple spatial scales, empirical predictions of TA had relatively high root mean square error >48 µmol kg−1. Additionally, ten stations displayed tidal variability in TA that was not likely driven by low TA freshwater inputs. As such, TA cannot be predicted accurately from salinity using a single relationship across the northeastern US region, though predictions may be viable at more localized scales where consistent freshwater and seawater endmembers can be defined. There was a high degree of geographic heterogeneity in both mean and tidal variability in TA, and this single-day snapshot sampling identified three patterns driving variation in TA, with certain locations exhibiting increased risk of acidification. The success of Shell Day implies that similar community science based events could be conducted in other regions to not only expand understanding of the coastal carbonate system, but also provide a way to inventory monitoring assets, build partnerships with stakeholders, and expand education and outreach to a broader constituency.
Continue reading ‘Synoptic assessment of coastal total alkalinity through community science’Does ocean acidification make marine fish grow differently? What about sex-specific effects?
Published 10 February 2021 Web sites and blogs ClosedThe question of whether ocean acidification (OA) will impact the growth of marine fish remains surprisingly uncertain. The bulk of available evidence in the form of laboratory experiments suggests that most fish are not impacted by OA-relevant CO2 levels, but many studies suffer from the inherent methodical constraints of rearing marine fish in captivity. For example, most experiments cover a small fraction of a species’ lifespan and do not employ restricted feeding regimes which may enable fish to increase feeding to offset metabolic deficits associated with high-CO2 acclimation.
Continue reading ‘Does ocean acidification make marine fish grow differently? What about sex-specific effects?’Seaweed farms provide refugia from ocean acidification
Published 10 February 2021 Science ClosedTags: algae, biological response, chemistry, field, mitigation, North Pacific
Seaweed farming has been proposed as a strategy for adaptation to ocean acidification, but evidence is largely lacking. Changes of pH and carbon system parameters in surface waters of three seaweed farms along a latitudinal range in China were compared, on the weeks preceding harvesting, with those of the surrounding seawaters. Results confirmed that seaweed farming is efficient in buffering acidification, with Saccharina japonica showing the highest capacity of 0.10 pH increase within the aquaculture area, followed by Gracilariopsis lemaneiformis (ΔpH = 0.04) and Porphyra haitanensis (ΔpH = 0.03). The ranges of pH variability within seaweed farms spanned 0.14-0.30 unit during the monitoring, showing intense fluctuations which may also help marine organisms adapt to enhanced pH temporal variations in the future ocean. Deficit in pCO2 in waters in seaweed farms relative to control waters averaged 58.7 ± 15.9 μatm, ranging from 27.3 to 113.9 μatm across farms. However, ΔpH did not significantly differ between day and night. Dissolved oxygen and Ωarag were also elevated in surface waters at all seaweed farms, which are benefit for the survival of calcifying organisms. Seaweed farming, which unlike natural seaweed forests, is scalable and is not dependent on suitable substrate or light availability, could serve as a low-cost adaptation strategy to ocean acidification and deoxygenation and provide important refugia from ocean acidification.
Continue reading ‘Seaweed farms provide refugia from ocean acidification’The effects of ocean acidification on marine life
Published 9 February 2021 Web sites and blogs Closed
What are the effects of ocean acidification? What role does an increase in oceanic acidity play in the biodiversity of marine life?
The effects of ocean acidification are so destructive that it’s been dubbed the global warming’s “evil twin.” Specifically, ocean acidification is causing an unprecedented reduction in oceanic biodiversity as tehe increased CO2 concentration is affecting the internal processes of the marine microbiome.
Continue reading ‘The effects of ocean acidification on marine life’Ocean acidification may slow the pace of tropicalization of temperate fish communities
Published 9 February 2021 Science ClosedTags: abundance, algae, biological response, BRcommunity, community composition, echinoderms, field, fish, otherprocess, South Pacific, vents
Poleward range extensions by warm-adapted sea urchins are switching temperate marine ecosystems from kelp-dominated to barren-dominated systems that favour the establishment of range-extending tropical fishes. Yet, such tropicalization may be buffered by ocean acidification, which reduces urchin grazing performance and the urchin barrens that tropical range-extending fishes prefer. Using ecosystems experiencing natural warming and acidification, we show that ocean acidification could buffer warming-facilitated tropicalization by reducing urchin populations (by 87%) and inhibiting the formation of barrens. This buffering effect of CO2 enrichment was observed at natural CO2 vents that are associated with a shift from a barren-dominated to a turf-dominated state, which we found is less favourable to tropical fishes. Together, these observations suggest that ocean acidification may buffer the tropicalization effect of ocean warming against urchin barren formation via multiple processes (fewer urchins and barrens) and consequently slow the increasing rate of tropicalization of temperate fish communities.
Continue reading ‘Ocean acidification may slow the pace of tropicalization of temperate fish communities’Impacts of climate change on methylmercury formation and bioaccumulation in the 21st century ocean
Published 9 February 2021 Science ClosedTags: biological response, BRcommunity, chemistry, globalmodeling, modeling, phytoplankton, primary production
Highlights
- Seawater MeHg may increase in the polar oceans and decrease in the North Atlantic in 2100
- Plankton MeHg may increase at high latitudes and decrease at mid to low latitudes
- Ocean acidification leads to different spatial patterns compared with physical factors
Summary
Climate change-driven alterations to marine biogeochemistry will impact the formation and trophic transfer of the bioaccumulative neurotoxin methylmercury (MeHg) in the global ocean. We use a 3D model to examine how MeHg might respond to changes in primary production and plankton community driven by ocean acidification and alterations in physical factors (e.g., ocean temperature, circulation). Productivity changes lead to significant increases in seawater MeHg in the polar oceans and a decrease in the North Atlantic Ocean. Phytoplankton MeHg may increase at high latitudes and decrease in lower latitudes due to shifts in community structure. Ocean acidification might enhance phytoplankton MeHg uptake by promoting the growth of a small species that efficiently accumulate MeHg. Non-linearities in the food web structure lead to differing magnitudes of zooplankton MeHg changes relative to those for phytoplankton. Climate-driven shifts in marine biogeochemistry thus need to be considered when evaluating future trajectories in biological MeHg concentrations.
Continue reading ‘Impacts of climate change on methylmercury formation and bioaccumulation in the 21st century ocean’Community responses of intertidal foraminifera to pH variations: a culture experiment with propagules
Published 9 February 2021 Science ClosedTags: abundance, biological response, BRcommunity, community composition, growth, laboratory, mortality, otherprocess, protists
Calcifying organisms such as benthic foraminifera are susceptible to changes in ocean pH and alkalinity. Responses to these changes include variations in mortality, calcification rates or assemblage composition, which have been observed in field and experimental studies. Here we applied a growth experiment with benthic foraminiferal propagules under different pH conditions to gather insights into the effect of pH on the composition of grown assemblages. A homogeneous propagule assemblage from a local mudflat in Corfu Island (Greece) was exposed to a range of pH conditions (6.5, 7.2, 7.8 and 8.5) for 5 weeks. In a second experiment, the assemblages were first exposed to low and subsequently to high conditions for a total of 8 weeks. After termination of the experiments, we recorded high survivability and growth throughout the treatments. Analysis of the assemblage composition of the first experiments revealed a shift from porcelaneous dominated taxa in the higher pH treatments to an assemblage with higher numbers of agglutinated taxa in the lower pH treatments. Soft-shelled monothalamous species were common throughout. The second experiment revealed assemblages that were significantly dominated by porcelaneous taxa with monothalamous taxa being almost absent. The results of this study are congruent with other observations on changing assemblage compositions with changing pH from both laboratory and field studies. The fast response of the assemblages through activation of potentially dormant propagules adds insights into the mechanisms behind seasonal composition changes in naturally variable environments such as river estuaries. They also shed new light on possible effects of continuous decreases in ocean pH on shallow-water foraminiferal assemblages in future.
Continue reading ‘Community responses of intertidal foraminifera to pH variations: a culture experiment with propagules’High carbon dioxide to slow tropical fish move to cooler waters
Published 9 February 2021 Press releases ClosedUnder increasing global warming, tropical fish are escaping warmer seas by extending their habitat ranges towards more temperate waters.
But a new study from the University of Adelaide, published in Nature Climate Change, shows that the ocean acidification predicted under continuing high CO2 emissions may make cooler, temperate waters less welcoming.
“Every summer hundreds of tropical fish species extend their range to cooler and temperate regions as the waters of their natural habitat become a little too warm for comfort,” says lead author Ericka Coni, Ph.D. student in the University’s School of Biological Sciences. “For at least two decades, Australian temperate reefs have been receiving new guests from the tropics.
Continue reading ‘High carbon dioxide to slow tropical fish move to cooler waters’Southern ocean acidification and the Antarctic treaty system
Published 9 February 2021 Science ClosedTags: education, policy, review
This chapter explores how states party to Antarctic Treaty System instruments have addressed ocean acidification in the Southern Ocean. While there are no obligations explicitly applicable to ocean acidification, states should address the threat as part of their obligations to comprehensively protect Antarctica and its dependent and associated ecosystems, and to apply an ecosystem approach to managing Southern Ocean fisheries. The Chapter provides a critical overview of ATS initiatives to date to develop a strategic policy approach to climate change, noting the significant resistance from states to developing substantive obligations within the ATS in respect of activities taking place outside of the Antarctic Treaty area. It concludes by arguing that Article 2 of the 1991 Environmental Protocol can be interpreted to impose a due diligence obligations on parties to take action to address the causes of ocean acidification in respect of activities outside of the Antarctic Treaty area.
Continue reading ‘Southern ocean acidification and the Antarctic treaty system’Influence of ocean acidification and warming on DMSP & DMS in New Zealand coastal water
Published 8 February 2021 Science ClosedTags: chemistry, laboratory, mesocosms, multiple factors, temperature
The cycling of the trace gas dimethyl sulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) may be affected by future ocean acidification and warming. DMSP and DMS concentrations were monitored over 20-days in four mesocosm experiments in which the temperature and pH of coastal water were manipulated to projected values for the year 2100 and 2150. This had no effect on DMSP in the two-initial nutrient-depleted experiments; however, in the two nutrient-amended experiments, warmer temperature combined with lower pH had a more significant effect on DMSP & DMS concentrations than lower pH alone. Overall, this indicates that future warming may have greater influence on DMS production than ocean acidification. The observed reduction in DMSP at warmer temperatures was associated with changes in phytoplankton community and in particular with small flagellate biomass. A small decrease in DMS concentration was measured in the treatments relative to other studies, from −2% in the nutrient-amended low pH treatment to −16% in the year 2150 pH and temperature conditions. Temporal variation was also observed with DMS concentration increasing earlier in the higher temperature treatment. Nutrient availability and community composition should be considered in models of future DMS.
Continue reading ‘Influence of ocean acidification and warming on DMSP & DMS in New Zealand coastal water’
